refactor(llm): enhance a string of graph query method

[imbajin]

Main Changes

• [x] enhance vid k-neighbor query
• [x] enhance property k-neighbor query
• [x] limit edges to avoid super vertex expanding
• [x] fetch vids only instead of fetch all vertices (with property)
• [x] refactor the code logic / simplify it
• [x] enhance extract keywords logic with @vichayturen
• [x] filter single char & avoid match meanness words (compare distance)
• [ ] compress duplicate property output
• [ ] use better path for LLM to get the graph related info
• [ ] .....

[imbajin]

Follow #84 (merge it first), and maybe include some vid matching enhancement